If you've always wanted to roll a spliff the size of the Washington Monument, the Border Patrol may be able to help.

Border agents and related workers at ports of entry seized 17 million pounds of marijuana on the Southwest border between January 2005 and October 2011, according to records obtained by the Center for Investigative Reporting.

There's a lot of other fun stuff you could do with it, according the news outlet, which actually did math and stuff to figure this out.

If you rolled up all that mary jane, you could invite everyone on Earth over, give them two joints apiece (14.2 billion joints) and still have 2 billion joints left over for late night.

Perhaps most fitting of all, you could take those same joints and build an 11-foot tall fence along the entire expanse of the U.S.-Mexico border. Actually you could span it 359 times if you lined it with one single marijuana cigarette after another, according to CIR.

Funny as it all might seem, this is actually important.

A deal made with some Republican senators yesterday on immigration reform would call for doubling the size of Border Patrol's staff.

Illegal immigration has dropped off substantially since the 1990s and early 2000s. But all the same, Border Patrol staffing levels have doubled since 2005, and so has the annual budget for their parent agency, U.S. Customs and Border Protection (see these charts for more).

If immigration reform passes, one estimate says it will reduce illegal immigration by 25 percent overall. If border measures are successful, there will probably be more people overstaying visas than crossing illegally at the border.

So what will all those extra agents do with their time? If nothing else, they can always seize enormous amounts of marijuana.

Border Patrol actually goes after drugs of all types, but marijuana makes up the vast majority of seizures by weight. In the 2011 fiscal year, the 2.5 million pounds of pot the agency netted made up 99 percent of its total haul.

Of course, popular opinion tends to reject that war against marijuana.

More than half of Americans think marijuana should be completely legal, and two states -- Washington and Colorado -- have already legalized it. But the federal government still considers pot a "dangerous drug" on par with heroin.

So unless the "legalize it" movement figures out how to capitalize on that state-level momentum and counter the feds, don't expect the Border Patrol's marijuana seizures to stop any time soon.

Update, 1:40 p.m. I specified that the 17 million pounds of marijuana was seized along the Southwest border exclusively. It doesn't represent all pot seizures over that period.

I also corrected the headline: the 16.3 billion joints would built one 11-foot tall border fence and you could span the border 359 times by lining up each spliff. I had originally written that the joints would equal 359 fences.